Flu season is worsening and it's hit your household, bringing its coughing, aches and pains and feverish sleep. Most of the time, getting the flu and other respiratory viruses is a nuisance, not a life-threatening event. But influenza does kill anywhere between 3,000 and 49,000 people a year in the United States, including previously healthy young adults and children.

Rates of women who are opting for preventive mastectomies, such as Angeline Jolie, have increased by an estimated 50 percent in recent years, experts say. But many doctors are puzzled because the operation doesn't carry a 100 percent guarantee, it's major surgery -- and women have other options, from a once-a-day pill to careful monitoring.

“For many flu victims, staying at home, drinking fluids and taking acetaminophen is all that they need,” says Dr. Ralph Riviello, a Philadelphia emergency doctor who is president of the Pennsylvania Chapter of the American College of Emergency Physicians. “But there will be exceptions, and those people should seek immediate assistance.”

So when do you just tough it out, and when do you head for the emergency room, or call an ambulance? Here are some guidelines from the Centers for Disease Control and Prevention, the American Academy of Pediatrics and the Pennsylvania Medical Society.

Call 911 if:

You or a child has severe difficulty breathing

A child is making grunting noises with each breath

A flu patient has passed out or stopped breathing

The lips turn blue when the patient isn’t coughing

Go to the emergency room if:

A child is breathing fast or has trouble breathing

Skin has turned bluish

A child is not drinking enough fluids

A child is not waking up or not interacting

A child is too irritable to be held

Flu-like symptoms improve but then return with fever and worse cough — this can indicate a “secondary infection”

There’s fever with a rash

An infant cries with no tears or has very few wet diapers — this can indicate dehydration, which can kill quickly.

“An adult with difficulty breathing, chest or abdomen pain, dizziness, confusion, or severe vomiting needs to head to the emergency room,” Riviello says.

When to call the doctor:

If you or a child has flulike symptoms and a stiff neck, severe headache, severe ear pain or a very sore throat

If your child is younger than 3 months and has a temperature of 100.4 degrees Fahrenheit

When fever rises above 104 degrees Fahrenheit repeatedly for a child of any age

When fever persists for more than 24 hours in a child younger than 2 years.

If the fever lasts more than three days in a child age 2 or older.

If the child’s chest hurts even when he or she isn’t coughing

If the child’s ribs pull in with each breath (these are called retractions)

If the child can't take a deep breath because of chest pain

If the child has severe chest pain, has coughed up blood or is wheezing

When do you know it's over?

“CDC recommends that you stay home for at least 24 hours after your fever is gone except to get medical care or for other things you have to do and no one else can do for you. (Your fever should be gone without the use of a fever-reducing medicine, such as Tylenol.) You should stay home from work, school, travel, shopping, social events, and public gatherings,” CDC advises.